Soybeans have been found to contain both isoflavonoids and lignans. These diphenolic compounds have in numerous experiments in vitro with cell cultures and in animal experiments been shown to have antiproliferative properties with regard to many types of cancer and have been shown to stimulate differentiation of many leukemic cell lines. In addition they have many other biological effects making them strong candidates for a role as cancer protective agents. The aim of the present investigation is to continue to develop methodology for quantitative measurements of lignans and isoflavonoids in human biological fluids and food specimens using immunological and GC-MS techniques. Polyclonal and monoclonal antibodies will be produced for genistein, daidzein, equol and enterolactone. The main goal is to simplify the techniques making it possible to study larger populations. When these methods are ready it is intended to measure these compounds in already collected plasma samples of groups of young and old women consuming different types of habitual diets (lactovegetarians, omnivores) and two groups of women having been operated for early breast cancer. These samples are unique because we have complete dietary records and assay results for isoflavonoids and lignans in urine as well as for a great number of other steroid and peptide hormones in plasma, urine and feces (more than 50 components). Furthermore it is intended to continue studies on the antiproliferative effects and mechanism of action of phytoestrogens including mammalian lignans and their precursors, which have been synthesized by us, on malignant cell lines using modern techniques. We intend to study particularly human breast, prostate, endometrium and liver cancer cells. These studies will be carried out by adding the compounds alone to cell cultures or in combination or combined with various estrogens, testosterone, antiestrogens, compounds binding to the type II estrogen binding site and antiestrogen binding site, which all have been synthesized already. Simultaneously we measure various proteins like prostatic specific antigen or sex hormone binding globulin in the medium and use molecular biology techniques for clarifying mechanisms. We will also continue the synthesis of reference compounds and deuterium- labelled compounds for GC-MS work as well as labels for time-resolved immunoassay and radioimmunoassay. The work involves synthesis of antigens for production of polyclonal and monclonal antibodies. This laboratory in close collaboration with the Department of Chemistry at the same university since 15 years has provided numerous deuterated and nondeuterated standards of lignans and isoflavonoids to research groups in many countries, mainly to research groups in USA. This we will continue if we can get continuation of the grant support.